The datetime design pattern the microformats people came up with is similar, but uses ISO 8601 for the timestamp in the title attribute.

Use of an abbr element instead of a span will work, although there are accessability concerns with using abbr in the way the microformat is using it.

My javascript code cannot currently parse 8601 dates. The nice thing about the date format I'm using is it can piggyback on javascript's built-in date parser.

Also, html 5 actually has a time element, although it looks to me like there's no way to specify you want one to be displayed as a relative date. (My javascript could be adapted to handle them though.) --Joey